MOSCOW (RFE/RL) - Russian opposition activists paid tribute to Aleksandr Litvinenko on the second anniversary of the former Russian security agent's death in London from radiation poisoning.

Some 30 activists are reported to have gathered in Moscow and accused Russian authorities of ordering the murder of Litvinenko.

Litvinenko died in a London hospital on November 23, 2006, after being poisoned by the radioactive substance polonium-210.

The former Russian security agent considered by British investigators to be a key suspect in the murder, Andrei Lugovoi, was quoted Saturday on Ekho Moskvy radio as saying he is ready to possibly go to Britain to encourage authorities to accelerate the investigation.

Lugovoi's offer was dismissed as a public relations "stunt" by Alex Goldfarb, a former associate of Litvinenko's and the author of a book on the murder.

Lugovoi, who was elected to the State Duma lower house of parliament last year, has been charged with murder by British prosecutors, but Russian authorities have refused to extradite him, saying this is not allowed under Russian law.Compiled from agency reports